Combustion Synthesis of Crystalline SiC Nanofibres: Process Characterization
|Andrzej Huczko 1, Magdalena Osica 1, Michał Bystrzejewski 1, Hubert Lange 1, Stanisław Cudziło 2|
1. Warsaw University, Faculty of Chemistry, Pasteura 1, Warszawa 02-093, Poland
SiC as an outstanding large-gap semiconductor exhibits a set of unique physical and chemical parameters, which makes it a promising candidate for numerous applications. If SiC were fabricated in the form of 1-D nanocrystallites, it would have new properties resulting from both its marked shape-specific and quantum-confinement effects. In this presentation, we describe the spontaneous formation of 1-D SiC nanostructures by silicon dehalogenation of poly(tetrafluoroethylene). The growth of nanofibres is initiated by the combustion synthesis in the Si-PTFE system. This process is based on the fact that the strong exothermic reaction propagates rapidly through the mixture of solid reactants. Rapid cooling of the products can lead to nucleation of 1-D nanocrystallites without any growth [1,2].
The synthesis process itself was monitored by emission spectroscopy measurements to evaluate reaction temperature and pressure control to calculate the pressure histories of combustion.
The effect of process variables, as reactants characteristics and ratio, initial pressure and combustion environment, reactor configuration, etc., on the reaction yield was studied.
The as obtained products were characterized by electron microscopy, Raman spectroscopy, XRD diffraction, and chemical analysis. The β-SiC nanofibres ca. 20-100 nm in diameter and up to 20 μm in length (see the Figure) were the main component of solid reaction products. The conversion degree above 90% of starting elemental Si, was obtained. The technique to purify chemically (up to 98%) the SiC nanofibres was elaborated.
SEM images of SiC nano fibre TEM images of a SiC nanofibre
This work was supported by the Ministry of Science and Education through the Department of Chemistry, Warsaw University under Grant No. 4T08D 021 23.
 A. Huczko et al., J. Phys. Chem., 2005, 109, 16244
 S. Cudziło et al., Carbon, 2005, 43, 1778
Presentation: Oral at Joint Fith International Conference on Solid State Crystals & Eighth Polish Conference on Crystal Growth, by Andrzej Huczko
See On-line Journal of Joint Fith International Conference on Solid State Crystals & Eighth Polish Conference on Crystal Growth
Submitted: 2007-01-19 18:19 Revised: 2009-06-07 00:44